Liquid-crystalline medium and liquid-crystal display comprising the same

Liquid-crystalline medium having a nematic phase and a dielectric anisotropy (Δε, at a temperature of 20° C. and a frequency of 1 kHz) of 0.5 or more which comprises:

• one or more compounds of formula I
• in which
• n denotes 0 or 1,
• R11 denotes R1,
• R12 denotes X1,
• R1 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms, and
• Xl denotes F, Cl, fluorinated alkyl, fluorinated alkenyl, fluorinated alkoxy or fluorinated alkenyoxy;
• and
• one or more compounds selected from the group of compounds of formulae II, III, IV and V:
• in which
• R2 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl. alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,
• on each appearance, independently of one another,
• L21 and L22 denote H or F,
• X2 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms,
• m denotes 0, 1, 2 or 3,
• R3 denotes alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms and
• on each appearance, independently of one another, are
• L31 and L32, independently of one another, denote H or F,
• X3 denotes halogen, halogenated alkyl or alkoxy having 1 to 3 C atoms or halogenated alkenyl or alkenyloxy having 2 or 3 C atoms, F, Cl, —OCF3, —OCHF3, —O—CH2CF3, —O—CH═CF2,—O—CH═CH2 or —CF3,
• Z3 denotes —CH2CH2—, —CF2CF2—, —COO—, trans-CH═CH—, trans-CF═CF—, —CH2O— or a single bond, and
• n denotes 0, 1, 2 or 3,
• in which
• R41 and R42, independently of one another, denote alkyl, alkoxy, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms, alkenyl, alkenyloxy, alkoxyalkyl or fluorinated alkenyl having 2 to 7 C atoms,
• independently of one another and, if
• occurs twice,
• also these independently of one another, denote
• Z41 and Z42, independently of one another and, if Z41 occurs twice, also these independently of one another, denote —CH2CH2—, —COO—, trans -CH═CH—, trans-CF═CF—, -CH2O—, —CF2O—, —C≡C— a single bond,
• P denotes 0, 1 or 2, and
• R51 and R52, independently of one another, have one of the meanings given for R41 and R42,
• if present, each, independently of one another, denote
• z51 to Z53 each, independently of one another, denote —CH2—CH2—, —CH2—O—, —CH═CH—, —C≡C—, —COO— a single bond, and
• i and j each, independently of one another, denote 0 or 1;
• with the condition that the ratio of the dielectric constant perpendicular to the director (ε⊥) to the dielectric anisotropy (Δε), i.e. (ε⊥/Δε) of the medium, is 2.0 or less.